The present invention relates generally to large gun systems.
Conventional indirect fire gun systems fire "dumb bullets" where the bullets follow a trajectory based on gun muzzle velocity and the direction the gun barrel is pointed. As with all conventional gun systems shooting dumb bullets, it's systems effectiveness, defined by its range and accuracy and rate of fire, are to a great extent limited to what the gun barrel and gun pointing system can provide. Since bullets of these larger gun systems can weigh 70 lb. and more, are over 4 inches in diameter, and often stand more that 4 feet tall, conventional gun systems also require complicated loading systems that expose people to the dangers associated with loading and handling these munitions. An additional problem of these larger gun systems is that all of the bullets need to be fired out of a single barrel, thereby creating a single point failure possibility of the entire gun systems. Even when the gun system is properly operating, simple physics involved with gun barrel heating and the related loss of mechanical strength of the material at too high of a temperature, often is the limiting factor in gun system rate of fire, one of the critical performance parameters of the gun.
Currently there are gun launched guided munitions, so called "smart bullets" being developed that, much like missiles that have been used for years, once they are launched from the gun they are actively guided to a preprogrammed target. Many are also being fitted with rocket motors that light off at a preset time interval once leaving the gun, thereby further increasing the range of these munitions. Properly designed, these rocket motors require less muzzle velocity, and less internal gun pressure, to achieve the desired range. These smart bullets achieve their longest range when fired at or near vertical position of the gun barrel. A big problem that has been identified by the gun community is that these guided projectiles have a limited shelf life once they leave the environmental protection of their shipping container. In the container the shelf life of the guided rounds can approach 10+ years however out of the container the shelf life is estimated at about 1 year.
Current military battle threats are defeated one of two ways: missiles or indirect fire guns lobbing in munitions at a target. Missiles are typically very expensive, $500,000 and up per missile is not unrealistic, and have ranges of up to hundreds of miles. These missiles are typically used on far out targets, and when guided are very accurate. Indirect fire guns usually have ranges limited to 20 miles or less and usually cost a couple of thousand dollars per round. They are also typically not very accurate and thus required a large amount of rounds to defeat the target. For threats that are at 20 to 100 miles the only current option is to fire a very expensive missile. It is desirable to be able to defeat a target 20 to 100 miles out with something less expensive than missiles. It is also desirable to be more accurate at hitting targets in the gun range thus requiring less munitions, and thus less overall cost, to defeat the close target. It is also more desirable to reduce manpower requirements of the gun and loading system while increasing the overall reliability.